Table 6.

Local maxima for LV 5: easy versus hard retrieval main effect

Temporal lag	Bootstrap ratio	Spatial extent	Talairach coordinates			HEM	Gyral location	Brodmann area	Significant post hoc ANOVA results
			x	y	z
Easy > hard
Left hemisphere
3	5.42	197	−35	−26	59	Left	Precentral gyrus	4
2, 4	5.19	81	−46	−29	58	Left	Postcentral gyrus	2
3	4.02	10	−9	−21	45	Left	Medial frontal gyrus	6
3	3.92	11	−12	40	40	Left	Superior frontal gyrus	8
Right hemisphere
2	4.13	71	43	−32	42	Right	Inferior parietal lobule	40
Hard > easy
Left hemisphere
4	−5.41	112	−39	2	43	Left	Middle frontal gyrus	6
3	−3.84	11	−45	−56	−16	Left	Fusiform gyrus	37*	R: group × difficulty and group × task
3	−3.62	10	−31	39	15	Left	Middle frontal gyrus	46*	R: difficulty
Right hemisphere
2–4	−9.97	758	13	−92	3	Right	Cuneus	17*	R: task × difficulty

Note: Temporal lag represents the time after event onset, when a cluster of voxels exhibited a contrast effect of interest. The bootstrap ratio threshold was set to ±>3.28, and identified dominant and stable activation clusters. The spatial extent refers to the total number of voxels included in the voxel cluster (threshold = 10).The stereotaxic coordinates are measured in millimeters, and gyral location and Brodmann areas (BAs) were determined by referring to Talairach and Tournoux (1988). The last column presents the highest order significant effect (P < 0.05) observed from the ROI-based post hoc group × task × difficulty repeated-measures ANOVAs. Regions marked with * were ROIs for which mean activity was extracted and plotted in a bar graph. R, significant effects for retrieval activity; HEM, cerebral hemisphere in which the activation occurred.